Integration whit OCSR2 "call Fail after 30 Second"

[Artemisio Stellato]

Hello to all,

I'm  doing an integration with OCS R2 (without using B2B), everything works  fine, but if I call from one end-point to the MOC, the call drops after  30 seconds. If MOC call end-point all work fine.

I checked several times the DNS configuration and everything works (including reverse zone).

Someone have any suggestions?

Best Regards

[awinter2]

SIP call drops after 30 seconds are normally caused by an outstanding ACK request in relation to the INVITE.

When calling from an endpoint registered on the VCS side towards MOC, the OCS Gateway VCS would be responsible for sending that ACK. The most probable cause for the missing ACK in this case would be that the VCS is unable to look up the OCS FEP DNS address, or for another reason being unable to deliver the ACK to the FEP.

The ACK should be sent to the topmost entry in the record-route header set in the 200 OK response for the INVITE sent towards OCS.